As for map data used by map display application software for a mobile phone, its capacity is compact, and a mobile phone downloads its surrounding map data from a server managing the map data and executes map display. In addition, since the server updates the map data for a mobile phone, it usually updates the map data to information newer than a common onboard navigation apparatus which uses the map data stored in a storage medium such as a DVD or HDD that stores the map data about a map or POI (Point Of Interest) information.
However, since the mobile phone has a smaller display, it has a disadvantage that when scrolling its map, it cannot provide a broad view of positional relationships between its own position and a scrolled spot. Furthermore, when altering a scale of a map or scrolling it, since the mobile phone downloads the map from the server, it takes a longtime to display the map, offering a problem of being not easy for a user to use.
On the other hand, as for the onboard navigation apparatus installed in a vehicle, since it can use sensor information on the vehicle side, it has higher position accuracy. Furthermore, since the onboard navigation apparatus has a much larger display screen than the mobile phone, and can use a higher performance arithmetic unit for the display processing and use the map data stored in a storage unit readable from the apparatus, it has higher scrolling speed of the map and can enable the user to learn the positional relationships between its own position and the scrolled spot more easily.
Accordingly, as a system combining the advantages of the two devices described above, a navigation apparatus has been proposed recently which applies the map display application software for the mobile phone to the onboard information system that has car navigation functions and is mounted on the vehicle.
For example, a Patent Document 1 discloses an information transfer apparatus in which a mobile data terminal such as a mobile phone with a small-sized display screen acquires position information such as GPS (Global Positioning System) information, traffic information and destination information from the onboard information system, and executes navigation processing. The apparatus implements the navigation functions of the mobile phone, which are easy to use for a user, by exchanging the position information and POI information between the mobile phone and the vehicle side.
In addition, a Patent Document 2 discloses a system in which a mobile phone records position data (POI information) received from a car navigation system and phone numbers corresponding to it in a telephone directory as telephone directory information, and retrieves, when receiving the position data from the car navigation system, the telephone directory information by matching the received position data with the position data corresponding to the phone number.
Thus, by recording the position data in association with the telephone directory information such as a phone number and name which is used for a telephone originally, the system can directly set the position data in accordance with the phone number and name or the like. In addition, it can retrieve a phone number and name by matching the position data received from the navigation system with the position data recorded in the telephone directory information in advance.
Furthermore, a navigation apparatus disclosed in a Patent Document 3 makes it easier, in a navigation apparatus such as a PND (Portable Navigation Device) having a display with a small display screen, to understand positional relationships between the position of the vehicle and a destination by connecting a reference point (the position of the vehicle, for example) on the map display with a scrolled position or the destination by a line segment to make their positional relationships clearer.